Quote the section of the Law that states Jesus is our Passover and after you do that then reconcile Acts 15 with the Law. If trangressing of the Law is sin and you trangress any part of the Law you are guilty of the whole Law.
Jeremiah 31:31-34
31 "Behold, days are coming," declares the LORD, "when I will make a new covenant with the house of Israel and with the house of Judah, 32 not like the covenant which I made with their fathers in the day I took them by the hand to bring them out of the land of Egypt, My covenant which they broke, although I was a husband to them, "declares the LORD. 33 "But this is the covenant which I will make with the house of Israel after those days," declares the LORD, "I will put My law within them, and on their heart I will write it; and I will be their God, and they shall be My people. 34 "And they shall not teach again, each man his neighbor and each man his brother, saying, 'Know the LORD,' for they shall all know Me, from the least of them to the greatest of them," declares the LORD, "for I will forgive their iniquity, and their sin I will remember no more." NAS
Hebrews 7:11-17
11 Now if perfection was through the Levitical priesthood (for on the basis of it the people received the Law), what further need was there for another priest to arise according to the order of Melchizedek, and not be designated according to the order of Aaron? 12 For when the priesthood is changed, of necessity there takes place a change of law also. 13 For the one concerning whom these things are spoken belongs to another tribe, from which no one has officiated at the altar. 14 For it is evident that our Lord was descended from Judah, a tribe with reference to which Moses spoke nothing concerning priests. 15 And this is clearer still, if another priest arises according to the likeness of Melchizedek, 16 who has become such not on the basis of a law of physical requirement, but according to the power of an indestructible life. 17 For it is witnessed of Him,
"Thou art a priest forever
According to the order of Melchizedek."
NAS
Leviticus 19:33-34
33'When a stranger resides with you in your land, you shall not do him wrong. 34'The stranger who resides with you shall be to you as the native among you, and you shall love him as yourself; for you were aliens in the land of Egypt: I am the LORD your God. NAS
Tradition is not the Law and by appealing to the traditions of the Jews you are widening the focus of "trangressing the Law is sin".
In Acts 10 Peter has a vision where God instructs Peter to kill and eat of unclean animals, which Peter later understands to mean the gentiles are to be given the message of Jesus and accepted into the Christian community. This vision also indicates the no food eaten by gentiles is unclean, which brings us to Galatians and Peter's hypocrisy since the ony part of the Law that Peter was violating by eating with the genitles was eating foods listed as unclean in Leviticus.